// Copyright (C) Kumo inc. and its affiliates.
// Author: Jeff.li lijippy@163.com
// All rights reserved.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
//

#pragma once

#include <turbo/base/macros.h>

namespace nebula::detail {

    class TURBO_EXPORT FingerPrintAble {
    public:
        virtual ~FingerPrintAble();

        const std::string &fingerprint() const {
            auto p = fingerprint_.load();
            if (TURBO_LIKELY(p != nullptr)) {
                return *p;
            }
            return load_fingerprint_slow();
        }

        const std::string &metadata_fingerprint() const {
            auto p = metadata_fingerprint_.load();
            if (TURBO_LIKELY(p != nullptr)) {
                return *p;
            }
            return load_metadata_fingerprint_slow();
        }

    protected:
        const std::string &load_fingerprint_slow() const;

        const std::string &load_metadata_fingerprint_slow() const;

        virtual std::string compute_fingerprint() const = 0;

        virtual std::string compute_metadata_fingerprint() const = 0;

        mutable std::atomic<std::string *> fingerprint_{nullptr};
        mutable std::atomic<std::string *> metadata_fingerprint_{nullptr};
    };
}  // namespace nebula::detail
